My planes always land before I want them too...
Probably ought to send the receiver in and have it checked out for other damage but,
It is very easy to replace the antenna. It is better to replace than to splice!!!
Assuming you can solder...
All you need is 39" of small stranded copper wire. (From Radio shack, etc.) Or you could buy JR part number JRPA170 from your hobby shop...
Just open up the receiver and solder it on in the same spot as the old one. Be sure to pre-tin the wire with shiny solder and get a good joint on the receiver itself.
Do good ground range tests with the repaired receiver. With the engine running and not running. Should be about the same range. If range is much better with the engine off, you may have done other invisble damage to the receiver which would require service from professionals.